Makes no difference. According to an English ex-pat that lives near me, you are not allowed to defend yourself openly in the UK. When your home is broken into, you are to retreat to your bedroom and lock the door. If the attacker comes in the bedroom, you may use only the same force to repel the attack. If he has a 6" knife, you can use a 6" or smaller knife but you will be charged if you use a knife longer than 6". The English has allowed themselves to be screwed.